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Sep 27, 2020 at 12:19 comment added user164442 how many connected components does your thing have?
Sep 25, 2020 at 12:09 history edited user30211 CC BY-SA 4.0
edited title
Sep 25, 2020 at 7:29 comment added Piotr Achinger I'm okay with a broad scope, I was more concerned with the set of possible precise formulations of your question being empty.
Sep 25, 2020 at 5:08 comment added Denis Nardin @DeanYoung Can you give a pointer to where the pro-smooth topos of $\mathrm{Spec}\,\mathbb{Z}\cup\{\infty\}$ is defined? I have no idea of what you're referring to. Note that $\mathrm{Spec}\,\mathbb{Z}\cup\{\infty\}$ is not a scheme, so the general definitions do not apply.
Sep 24, 2020 at 22:53 comment added user30211 I like to think in terms of the pro-smooth topos (filtered limits of smooth maps). This might not have a candidate for a weakly contractible cover, though (I haven’t found one). Certainly the ordinary smooth topos does not. I respect your concern for a grounded question. But it seems from what @DenisNardin is saying that in choosing the topos, I might only get one or a few of the proposals and a limited perspective. I would much rather hear a broad answer overviewing the current state of the literature than limit myself to a partial view by committing myself to a particular topos.
Sep 24, 2020 at 13:15 comment added Piotr Achinger This question has already 5 upvotes but still doesn't make sense. Please clarify what you mean by $\operatorname{Spec} \mathbf{Z} \cup \{{\rm place}_\infty\}$ or its etale homotopy type.
Sep 24, 2020 at 2:05 history edited user30211 CC BY-SA 4.0
edited title
Sep 23, 2020 at 6:14 comment added Denis Nardin What topos corresponds to $\operatorname{Spec}(\mathbb{Z})\cup\{\infty\}$? I know of a couple of proposals, but they're both in a rather embrional stage...
Sep 23, 2020 at 5:34 comment added naf What is your definition of etale homotopy type after adding the infinite place?
Sep 23, 2020 at 3:18 comment added David Roberts no probs, that would make it a different question :-)
Sep 23, 2020 at 0:52 history edited user30211 CC BY-SA 4.0
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Sep 23, 2020 at 0:50 comment added user30211 @DavidRoberts I intended to compactify it first; I hope you don't mind if I change it to $\text{Spec}(\mathbb{Z}) \cup \{ \text{place}_{\infty} \}$.
Sep 23, 2020 at 0:06 review Close votes
Sep 23, 2020 at 20:13
Sep 22, 2020 at 23:48 comment added David Roberts Does this answer your question? What are the higher homotopy groups of Spec Z ?
Sep 22, 2020 at 23:44 comment added David Roberts shall we close this as duplicate?
Sep 22, 2020 at 21:01 comment added user30211 Shoot, I intended to compactify.
Sep 22, 2020 at 20:56 comment added David Roberts Ok,. Try this: mathoverflow.net/a/186140/4177
Sep 22, 2020 at 20:53 comment added David Roberts And $\pi_1=0$ ?
Sep 22, 2020 at 19:47 history asked user30211 CC BY-SA 4.0